Warning signal



March 12, 1935. W, g 1,994,426

WARNING S IGNAL Filed May 18, 1933 Patented Mar. 12, 1 935 i UNITEDSTATES PATENT OFFICE WARNING SIGNAL Fred wminm Blllig, Jackson, Michassignor to The Sparks-Withington Company, Jackson, Mich., a corporationof Michigan Application May 18, 1933, Serial No. 671,671 (Claims. (Cl.116-137) This invention relates to improvements in the diaphragm 1 andrigidly secured in any suit- Weming signals and pertains moreparticularly able manner to that portion of the diaphragm to that classof signals used on power-driven adjacent said opening. vehicles such asautomobiles, motorboats or the A sleeve 11 provided with an externallythreadlike. 1} ed portion is screw-threaded in the collar 10 so 5 Themain object of this invention is the proas to constitute a rigid portionof the diaphragm. duction of a warning signal having improved One end ofthe sleeve 11 projects forwardly from tone characteristics preferablyresulting in a the diap m a d is flattened 1111011 diametricalpleasingharmonious tone highly effective in at- 1y pp sit sid r th r pti n f adis or 10 tracting the attention of one to be warned. p e 12 which snell-eileuler Opening p 10 A further and important object resides in theed to fit over the end of the sleeve 11, said disk product on of -acomparatively simple construcbeing of suflicient diameter to extendacross the tion consisting of few parts, but constituting adjacent faceof the collar 10, and is adapted to rigid assembly and which can beeconomically be used to rotate the sleeve 11. The other endmanufactured. of the sleeve 11 extends inwardly some distance 15 Anotherobject of the invention is to produce from the diaphragm through theCentral p a signal of the above-mentioned class, which may ing in themagnet 5 into engagement with the be readily altered so as to producetones of higher armature or lower pitch so that the i al may b used Theinner end of the sleeve 11 is spherically in pairs, with the signals ofeach pair having shaped so as to seat tightly in a substantially 20tones of different pitch and which arein con- Similarly spherically p drecess in the i cord with each other. cent side of the armature 9. Thearmature 9 has Other objects and advantages pertainin t a central hole'13 extending therethrough in the details of the structure will appear 1t alignment with the interior of the sleeve 11 and followingdescription, taken in connection with i provided n e inner fa h e f wi ha 25 the accompanying drawing in which:-- recess in alignment with thehole 13 and which Figure 1 is a, perspective vi of a signal devicereceives a spacing collar 14 which has the inner embodying the variousfeatures oi this invention. face thereof in engagement w a washer 15Figure 2 is an enlarged longitudinal sectional interposed between the pin 11 4 and a so view taken substantially in the plane of the line leafspring 16 which is supported at one end by 2-2, Figure 1. a pedestal 17secured to or made integral with The warning signal, as illustrat d inth draw. the inner face of the case 2 at one side of the ing, is of themagnetically operated vibrating magnet Openingdiaphragm type d comprisesm;- In order that the spacing collar 14 and the 85 phragm 1 secured atits edge between a case 2 Washer 15 may v an adjustable firm Contact andth front covering or housing g bolts or with each other, the inner endof the collar 14 screws 4. Thecase 2 has its central porti is preferablyof convex form, while the adjacent dished and or substantiallycylindrical cup-shape, face of the washer 15 is concaved to conform towith the center of said cup-shaped portion prothe curvature of the001131 vided with an opening for the reception of a The p n Wa h r pa inl r 14, o magnet or magnetic field 5, The magnet. 5 may armature 9 andsleeve 11 are rigidly secured tobe secured to the case 2 in any suitablemanner gether in fixed relation with each other and with not hereinnecessary to illustrate or describe. the phragm 1 by means of head dbolt 19 The magnet 5 is provided with a central pasand a nut 20, saidbolt being extended upwardly sage 6 therethrough and a pair oftransversely through the sleeve l1,armature 9, collar 14,wash- 45disposed slots or grooves 7 formed in the rear er 15 and p in ,16. whith n 0 is s r wface thereof. These slots '1 are arranged one at threadedon the inner end portion of the bolt 19 either side of the passage 6 andsupportably rein contact with'the spring 16. I preferably proceivetherein a field coil 8. This field coil lies vide a washer as 21 uponthe bolt 19 between the wholly forward of the rear surface of themaghead of the bolt and the disk 12 for engaging 50 net 5. said disk asthe disk is clamped between the head The diaphragm 1 is provided with acentral of the bolt and the outer end of the collar 10 so opening inalignment with the opening 6 in the that when the sleeve 11 and theassociated parts magnet 5. An internally threaded reinforcing aresecured together by the bolt 19 and nut 20, collar or ring 10 ispositioned'in the opening in said disk 12 and the sleeve 11 will belocked in the adjusted position and thereby maintain the armature 9 andthe diaphragm 1 in fixed predetermined spaced relation for maintainingthe armature 9 in slightly spaced relation with the inner face of themagnet 5, as illustrated in Figure 2, when the diaphragm l is in thenormal at-rest position.

There is also provided a make and break mechanism for the circuit of thefield coil 8 and which consists of a pair of electrodes or contactmembers 23 and 24. One of the electrodes as 23 consists of a screwadjustably mounted in one end of a yoke 25 which has the other endsecured to the pedestal 1'7 in insulated spaced relation thereto, whilethe other electrode is a stud secured to the free end portion of a fiatspring member 26 which is secured to the pedestal 17 in insulated spacedrelation to the pedestal and also to the yoke 25.

The spring member or contact arm 26 extends inwardly from the contactmember 24 to within a short distance .of the upper end of the screw 19in the path of movement of a nut or actuating member 27 which isscrew-threaded on the upper end of the screw 19 and is locked to thescrew in predetermined relation with the inner end of the member 26 by,means of a lock nut 28 so that when the armature 9 is drawn towards themagnet 5, the electrodes 23 and 24 will be separated. The upper face ofthe contact arm 26 is preferably provided with an insulating materialfor maintaining the screw 19 and contact member 24 in insulated spacedrelation during the engagement of the actuating member 27 with thecontact arm 26.

A cover 29 is also provided for enclosing the magnet 5, the case 2 andthe parts associated therewith, said cover being secured in position bymeans of a U-shaped bracket 30 which extends diametrically across thecase 2, with the ends thereof secured to said case by the bolts 4 orother suitable means and a screw 31 which secures the cover 29 to thebracket 30.

The cover 29 may be provided with a suitable aperture as 29' throughwhich electrical conductors not shown may pass to the interior of thecase and be secured to suitable terminals, one of which is illustratedat 60, Figure 2, secured to the case 2.

A fixed condenser 34 is secured to one side of the magnet by a springclip 35, said condenser being electrically connected with the coil 8and. contacts 24 and 25 in any well-known manner not herein necessary tofurther illustrate or describe.

It will now be observed that the mechanism thus far describedconstitutes a conventionally constructed motor of the magnetic typeadapted to produce vibratory movement of the diaphragm 1 when electricenergy of proper potential is supplied to the coil 8.

The main features of this invention reside in the. form and constructionof the front covering or housing 3 and an air conduit as 3'? associatedwith the housing. It will be observed by referring to Figure 2 that thecentral portion of the diaphragm 1 is of serpentine formation incross-section and that the inner face of the housing 3 is also formedserpentine in cross-section to conform to the contour of the adjacentportion of the diaphragm 1.

The outer edge of the diaphragm 1 is preferably spaced from the housing3 by a ring or washer 38 so as to provide an air chamber 39 between thehousing 3 and the diaphragm 1. The central portion of the diaphragm, inthis instance, is spaced a greater distance from the adjacent portion ofthe housing 3 than the outer edge thereof so as to permit the freevibratory movement of the diaphragm as the armature 9 moves to and fromthe inner face of the magnet 5.

The housing 3 is also provided with a centrally located hollow boss 40which is adapted to receive the outer end of the screw 19 and collartherein. The boss 40 is internally threaded for receiving one end of anexternally threaded bracket 41 which may be secured to the housing 3 bya lock nut 42. The bracket 41 is provided with an air passage 43 whichextends from the inner end of the bracket outwardly and terminates atthe side of the bracket intermediate the ends thereof.

A tube 44 having the ends thereof return bent to form an-air columncoil, is removably secured at one end to the bracket. 41 by a nut 45 incommunication with the air passage 43, while the other end of the tube44 is removably secured by a nut 46 to the outer end of the bracket 41in communication with a transversely disposed passage 47 provided intheouter end of the bracket.

1 also provide a projector tube 49 which consists of a conical bodyportion 50 which has the smaller end thereof secured to the outer end ofthe bracket 41 in communication with the passage 4'7 and a bell portion51 which may be secured to the other or larger end of the tube 50 in anysuitable manner as by forming a bead 52 on the outer end of the portion50 and an annular groove 53 in the bell portion 50 adapted to receivethe bead 52 therein.

I also provide the projector 49 with a baflle screen 54 which consistsofwire mesh concavoconvex in cross-section, with the edge thereofremovably mounted in an annular recess formed at the interior of thebody portion 50 adjacent the bead 52.

It will now be observed that inasmuch as the loudness or intensity ofsound is proportionate to the force of the shock which the air receives,the density of the medium through which the air waves pass and theobstruction in the path of said air waves and that as pitch iscoordinate with force, timbre and duration, the tone of the signalingdevice may be readily changed by altering the thickness of the diaphragm1, the air gap between the armature 9 and magnet 5 and the length of theair column tube 44. In other words, by constructing the instrument asillustrated in the drawing, a low pitch tone is obtained, and when ahigh pitch tone is desired, it is only necessary to substitute for thediaphragm shown, one of a different thickness, to alter the air gapbetween the armature 9 and the magnet 5 by manipulating the sleeve 11relative to the diaphragm 1 and collar 10 and by providing an air columntube 44 of less length than the one illustrated in the drawing, andalthough I have shown and particularly described thepreferred embodimentof my invention, I do not wish to be limited to the exact constructionshown, as various changes both. in the form and relation of the partsthereof, may readily be made without departing from the spirit of thisinvention, as set forth in the appended claims.

I claim:

1. In a warning signal, a case, a diaphragm, a housing means securingthe diaphragm and housing to the case to form an air chamber adjacentone side of the diaphragm, a motor mounted on the case and operativelyassociated with the diaphragm for producing a vibratory movement of saiddiaphragm, and an air conduit for amplifying the sound waves produced bythe diaphragm comprising a bracket secured to the housing and having anair passage therein in communication with the chamber, a projector tubesecured to the bracket and an air column tube removably secured to thebracket with one end in communication with the interior of the projectortube and the other end in communication with th passage in the bracket.

2. In a warning signal, a diaphragm, a housing,

air passage spaced from the first-mentioned. air; passage, an air columntube secured to the bracket with each end thereof in communication witha respective air passage, a projector tube secured at one end to thebracket with the interior thereof in communication with saidtransversely disposed" air passage, and means for providing a vibratorymovement of said diaphragm.

3. A warning signal comprising in combination,

a diaphragm, a housing secured at one side of, the diaphragm to form anair chamber therebetween, said housing being provided with an openingleading outwardly from the air chamber, a bracket secured to the housingat said opening, said bracket being provided with an air passage thereinin communication with said opening, and a second air passage spaced fromthe first mentioned air passage, an air column tube secured to thebracket and operatively connecting said passages with each other, aprojector tube se-. cured at one end to the bracket with the interiorthereof in communication with said secondmentioned air passage and meansfor producing a vibratory movement of said diaphragm.

4. A warning signal comprising in combination a diaphragm, a housingmeans secured at one side of the diaphragm to form an air chambertherebetween, said housing means being provided with as air passageleading outwardly from the air chamber and a second air passage spacedfrom the first mentioned air passage, an air column tube secured to thehousing means and operatively connecting said air passages with eachother, a projector tube secured at one end to the housing means with theinterior thereof in communication with said second mentioned airpassage, and means for producing a vibratory movement of aid diaphragm.

FRED fl BILLIG.

